I posted the only engine picture I have. Don't think it could be ID from it. Just from talking to the owner, I would guess it is the correct carb. He has had it for 12 years, and had all the right work done. Replaced the exhaust manifolds recently as well.

Can't tell enough from that pic. Need to see the carb with the flame arrestor off. The only reason I brought that up is from your earlier post that said it has a double pumper carb, and marine applications don't normally use a double pumper carb. Again, I'm not a GM guy, so don't take my word as gospel.

Everything else looks great, even the fuel pump vent line running to the carb. I only bring up the non-original parts as my '77 came with non-marine starter and carb. As this was my first inboard, I didn't know the difference, but quickly learned the ropes from all the knowledgeable folks around here.